Force VisualBench to reset GLContext on GrContext reset

tools/VisualBench/VisualStreamTimingModule.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "VisualStreamTimingModule.h"
 
 #include "SkCanvas.h"
 
 VisualStreamTimingModule::VisualStreamTimingModule(VisualBench* owner, bool preWarmBeforeSample)
     : fInitState(kReset_InitState)
     , fPreWarmBeforeSample(preWarmBeforeSample)
     , fOwner(owner) {
     fBenchmarkStream.reset(new VisualBenchmarkStream);
 }
 
 inline void VisualStreamTimingModule::handleInitState(SkCanvas* canvas) {
     switch (fInitState) {
         case kNewBenchmark_InitState:
-            fOwner->clear(canvas, SK_ColorWHITE, 2);
             fBenchmarkStream->current()->delayedSetup();
             // fallthrough
         case kReset_InitState:
+            // This will flicker unfortunately, but as we are reseting the GLContext each bench,
+            // we unfortunately don't have a choice
+            fOwner->clear(canvas, SK_ColorWHITE, 2);
             fBenchmarkStream->current()->preTimingHooks(canvas);
             break;
         case kNone_InitState:
             break;
     }
     fInitState = kNone_InitState;
 }
 
 inline void VisualStreamTimingModule::handleTimingEvent(SkCanvas* canvas,
                                                         TimingStateMachine::ParentEvents event) {
@@ skipping 30 matching lines @@
         // TODO research why this does happen on mac
         return;
     }
 
     this->handleInitState(canvas);
     this->renderFrame(canvas, fBenchmarkStream->current(), fTSM.loops());
     fOwner->present();
     TimingStateMachine::ParentEvents event = fTSM.nextFrame(fPreWarmBeforeSample);
     this->handleTimingEvent(canvas, event);
 }